Basic Principles for WHM - What and what not to do.

[Sebazy]

I often see comments like "if the DPS just lost like 500 HP I'll toss a regen", which is terrible.

Wait what? All this time I should have been cure IIIing them?

Seriously though, regen is perfectly fine, it's the second lowest MP cost option we have and any further damage taken in the following 20 seconds will boost it's efficiency far beyond anything else this side of an opportunistic freecure.

At the risk of getting personal, you're off your trolley mate. Every single last ability we have could be classified as inefficient if you use it wrongly. Regen used appropriately is the most efficient bread and butter spell we have.